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WO2001096011A1 - Procede d'encapsulation reposant sur l'utilisation de fractions isocyanate - Google Patents

Procede d'encapsulation reposant sur l'utilisation de fractions isocyanate Download PDF

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Publication number
WO2001096011A1
WO2001096011A1 PCT/CA2001/000846 CA0100846W WO0196011A1 WO 2001096011 A1 WO2001096011 A1 WO 2001096011A1 CA 0100846 W CA0100846 W CA 0100846W WO 0196011 A1 WO0196011 A1 WO 0196011A1
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moieties
liquid
microcapsules
anhydride
reactants
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Inventor
Harald D. H. STÖVER
Anna Shulkin
Chandrika Mudalige
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McMaster University
3M Innovative Properties Co
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McMaster University
3M Innovative Properties Co
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Priority to AU2001267202A priority Critical patent/AU2001267202A1/en
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J13/00—Colloid chemistry, e.g. the production of colloidal materials or their solutions, not otherwise provided for; Making microcapsules or microballoons
    • B01J13/02—Making microcapsules or microballoons
    • B01J13/06—Making microcapsules or microballoons by phase separation
    • B01J13/14—Polymerisation; cross-linking
    • B01J13/16—Interfacial polymerisation
    • A—HUMAN NECESSITIES
    • A01—AGRICULTURE; FORESTRY; ANIMAL HUSBANDRY; HUNTING; TRAPPING; FISHING
    • A01N—PRESERVATION OF BODIES OF HUMANS OR ANIMALS OR PLANTS OR PARTS THEREOF; BIOCIDES, e.g. AS DISINFECTANTS, AS PESTICIDES OR AS HERBICIDES; PEST REPELLANTS OR ATTRACTANTS; PLANT GROWTH REGULATORS
    • A01N25/00—Biocides, pest repellants or attractants, or plant growth regulators, characterised by their forms, or by their non-active ingredients or by their methods of application, e.g. seed treatment or sequential application; Substances for reducing the noxious effect of the active ingredients to organisms other than pests
    • A01N25/26—Biocides, pest repellants or attractants, or plant growth regulators, characterised by their forms, or by their non-active ingredients or by their methods of application, e.g. seed treatment or sequential application; Substances for reducing the noxious effect of the active ingredients to organisms other than pests in coated particulate form
    • A01N25/28—Microcapsules or nanocapsules

Definitions

  • the present invention relates to microcapsules and to particles of a matrix, to methods of making them, and to their use.
  • Microcapsules and matrices containing an encapsulated active ingredient are known for many purposes. In some instances, slow release of the encapsulated ingredient is required.
  • Materials that have been encapsulated in microcapsules and hydrogel matrices include pharmaceuticals, pesticides, fungicides, herbicides, bactericides, dyes, inks, chemical reagents and flavouring materials, and semiochemicals, that is materials that will modify the behaviour of animal species, for example pheromones.
  • insect pheromones are proving to be a biorational alternative to conventional hard pesticides.
  • attractant pheromones can be used effectively in controlling insect populations by disrupting the mating process.
  • small amounts of species-specific pheromone are dispersed over the area of interest during the mating season, raising the background level of pheromone to the point where the male insect cannot identify and follow the plume of attractant pheromone released by his female mate.
  • Polymer microcapsules are some of the delivery devices used to deliver the pheromone throughout the mating period of the insect, typically two to six weeks.
  • Polymer microcapsules promise to serve as efficient delivery vehicles, as they: a) are easily prepared by a number of interfacial and precipitation polymerizations, b) enhance the resistance of the pheromone to oxidation and irradiation during storage and release, c) may in principle be tailored to control the rate of release of the
  • la pheromone fill and (d) permit easy application of pheromones by, for example, spraying, using conventional spraying equipment .
  • One known method of forming pheromone-filled microcapsules involves dissolving pheromone and a diisocyanate in xylene and dispersing this solution into an aqueous solution containing a diamine .
  • a polyurea membrane forms rapidly at the interface between the continuous aqueous phase and the dispersed xylene droplets, resulting in formation of microcapsules containing the pheromone and xylene; see for example PCT international application WO 98/45036, Li, Nielsen, Sengupta, published 15 October 1998.
  • Isocyanates are highly reactive compounds and it is at times difficult to encapsulate compounds that react with the isocyanate. For example, it is difficult to encapsulate compounds containing hydroxyl groups such as alcohols .
  • isocyanates are relatively expensive compounds and must be handled with care .
  • the present invention provides an encapsulation method in which use of an isocyanate may be reduced.
  • the invention provides a method of forming microcapsules or particles of a matrix which comprises dispersing a first liquid in a second, immiscible or partially miscible liquid that forms a continuous phase, one liquid containing reactants bearing (a) isocyanate moieties and (b) anhydride moieties, glycidyl moieties, or electrophilic moieties bearing base-susceptible leaving groups (e.g. alkyl or aryl halides, tosylates, acid chlorides) , and the other liquid containing a reactant that bears reactive groups that will react with the reactants in the said one liquid to form a membrane .
  • reactants bearing (a) isocyanate moieties and (b) anhydride moieties, glycidyl moieties, or electrophilic moieties bearing base-susceptible leaving groups (e.g. alkyl or aryl halides, tosylates, acid chlorides)
  • a material is to be encapsulated in the microcapsules or the particles of the matrix, that material is dissolved or dispersed in the first liquid that forms the dispersed phase.
  • the invention is particularly useful for encapsulating materials for which controlled release is needed, for instance, insect pheromones.
  • the invention relates to microcapsules or particles of a matrix formed by reaction, at an interface, between reactants bearing (a) isocyanate moieties and (b) anhydride moieties, glycidyl moieties or electrophilic moieties bearing base-susceptible leaving groups, and a reactant that bears reactive groups that will react with the reactants bearing (a) and (b) to form a membrane.
  • isocyanates can be reacted with amines to form membranes encapsulating mterials, which will undergo controlled release.
  • isocyanates it has not been known to use a combination of isocyanates and anhydride moieties, glycidyl moieties, or electrophilic moieties bearing base-susceptible leaving groups to form membranes for encapsulating materials.
  • SMA styrene-maleic anhydride
  • microcapsule walls consist of a combination of polyurea and SMA14-amine adduct, present in two distinct but interpenetrating phases .
  • These composite microcapsules combine the high wall strength provided by the polyurea component, with the higher release rates provided by the SMA14-amine component.
  • the present invention makes available many different morphologies of microcapsules. Hence, the properties of the walls of the microcapsules can be adjusted to modify the rate of release of the encapsulated material.
  • an anhydride moiety, glycidyl moiety, or an electrophilic moiety bearing a base-susceptible leaving group participates in reaction, it may replace an isocyanate moiety and may reduce the use made of the isocyanate.
  • the molar ratio of isocyanate moieties (a) to anhydride moieties, glycidyl moieties, or electrophilic moieties bearing base-susceptible leaving groups (b) can vary over a wide range. It is possible to have a ratio of (a) to (b) in the range 1:99 to 99:1, preferably 5:95 to 95:5, more preferably in the range 25:75 to 75:25.
  • the chemical composition of the membrane will of course affect its
  • the ratio of (a) to (b) can be selected to enhance particular properties.
  • the amount of isocyanate is in the range 25% to 75%, based on the total weight of (a) and (b) .
  • a reactant bearing isocyanate moieties (a) is a polyisocyanate such as a diisocyanate or a triisocyanate, or an oligomer.
  • the polyisocyanate may be aromatic or aliphatic and may contain two, three or more isocyanate groups.
  • aromatic polyisocyanates include 2,4- and 2, 6-toluene diisocyanate, naphthalene diisocyanate, diphenylmethane diisocyanate and triphenylmethane-p,p' ,p" -trityl triisocyanate.
  • Aliphatic polyisocyanates may optionally be selected from aliphatic polyisocyanates containing two isocyanate functionalities, three isocyanate functionalities, or more than three isocyanate functionalities, or mixtures of these polyisocyanates.
  • the aliphatic polyisocyanate contains 5 to 30 carbons. More preferably, the aliphatic polyisocyanate comprises one or more cycloalkyl moieties.
  • Examples of preferred isocyanates include dicyclohexylmethane- 4,4' -diisocyanate; hexamethylene 1, 6-diisocyanate; isophorone diisocyanate; trimethyl-hexamethylene diisocyanate; tri er of hexamethylene 1, 6-diisocyanate; trimer of isophorone diisocyanate; 1, 4-cyclohexane diisocyanate; 1, 4- (dimethyl- isocyanato) cyclohexane; biuret of hexamethylene diisocyanate; urea of hexamethylene diisocyanate; trimethylenediisocyanate; propylene-1, 2-diisocyanate; and butylene-1, 2-diisocyanate . Mixtures of polyisocyanates can be used.
  • polystyrene resin polystyrene resin
  • polystyrene resin polystyrene resin
  • Particularly preferred polyisocyanates are poly ethylene polyphenylisocyanates of formula:
  • n 2 to 4.
  • reactants complementary to isocyanate moieties there are mentioned polyols and polyamines. These are also reactants complementary to anhydride moieties, glycidyl moieties, and electrophilic moieties bearing base-susceptible leaving groups and are discussed further below.
  • an oligomer or a copolymer containing reactive anhydride moieties that can react with a polyamine or a polyol .
  • Sources of anhydride moieties include anhydride -containing compounds that also contain double bonds that can undergo polymerisation, for example maleic anhydride, itaconic anhydride, citraconic (methylmaleic) anhydride, ethylmaleic anhydride, 1,2- cyclohexene-1, 2-dicarboxylic acid anhydride and 1,2- cyclohexene-4, 5-dicarboxylic acid anhydride, of which maleic anhydride is preferred.
  • Maleic anhydride undergoes homopolymerisation only with difficulty and it is possible only to form low molecular weight oligomers.
  • Maleic anhydride dimer and maleic anhydride oligomer can be used as a reactant.
  • Maleic anhydride does readily undergo copolymerisation with other monomers, for example styrene, provided that the molar ratio of styrene to maleic anhydride is 1:1 or greater. This permits at least one styrene moiety to be located between any two maleic anhydride moieties, and eliminates the difficulty that occurs when attempts are made to homopolymerize maleic anhydride.
  • a preferred reactant is a maleic anhydride -containing copolymer.
  • Styrene-maleic anhydride copolymers are commercially available with maleic anhydride contents up to 50 mol%. Any styrene -maleic anhydride copolymer can be used.
  • the solubility properties of the styrene-maleic anhydride copolymer will depend on the maleic anhydride contents of the copolymer.
  • the solubility parameter of copolymer containing 50 mol% maleic anhydride is 10.1 (cal/cm 3 ) 1/2 , so the copolymer is soluble only in solvents with some degree of polarity, for instance ethyl acetate, methyl ethyl ketone, tetrahydrofuran, dichloromethane and butyronitrile .
  • Copolymer with 5 mol% maleic anhydride has a solubility parameter of 9.314 (cal/cm 3 ) 1 '' 2 and is soluble in these solvents, but also soluble in non-polar solvents such as toluene and xylene which, because of their immiscibility in water, are particularly suitable for use as the dispersed liquid if the continuous phase is aqueous.
  • Copolymer with 32 mol% maleic anhydride has a solubility parameter of 9.907 (cal/cm 3 ) 12 .
  • anhydride moieties in a copolymer that is prepared from an unsaturated co-polymerisable monomer other than styrene.
  • co-monomer ⁇ -methylstyrene, or styrene or -methylstyrene that is substituted in the benzene ring of the styrene moiety.
  • substituent mention is made of lower alkyl groups having up to 18 carbon atoms, preferably up to 6 carbon atoms. The extra alkyl substituents on, for example, p-methylstyrene and p- tert .
  • -butylstyrene render the copolymer less polar and more soluble in the water-immiscible solvents such as xylene and toluene that are commonly preferred for use in interfacial reactions.
  • Other possible unsaturated copolymerisable monomers that may be_present, in place of or in addition to styrene, include olefins such as ethylene, conjugated dienes such as 1, 3-butadiene and isoprene, alkyl acrylates and methacrylates, especially lower alkyl such as the methyl, ethyl and, preferably, the butyl and ethylhexyl esters, vinyl acetate, acrylonitrile, methacrylonitrile, acrylamides, methacrylamides and unsaturated ethers such as alkyl vinyl ethers, for instance, the methyl and ethyl ethers.
  • olefins such as ethylene, conjugated dienes such
  • vinyl sulphoxides and vinyl sulphones are also mentioned.
  • Mixtures of these can be used in the copolymerization to design copolymers that have particular solubility properties and, when reacted with polyamine or polyol, impart_particular properties to the membrane formed.
  • the molecular weight of the polymer may be greater than about 1,000, preferably greater than about 20,000. There is no critical upper limit on the molecular weight of the copolymer, provided that the viscosity does not increase to such an extent that reaction is impeded. Molecular weights greater than about 400,000 are not normaly used.
  • polymers bearing pendant glycidyl moieties can be formed by copolymerizing glycidyl acrylate or methacrylate with styrene or any of the other copolymerizable monomers mentioned above. The reaction of glycidyl moieties can again be catalysed by a tertiary amine that is dissolved in the continuous aqueous phase.
  • polymers that include electrophilic moieties bearing a base-susceptible leaving group An example is a polymer bearing chloromethyl moieties, where the chlorine serves as the leaving group. Chloromethylstyrene can be copolymerized with any of the copolymerizable monomers discussed above.
  • Suitable reactants that will react with isocyanates and with anhydride moieties, glycidyl moieties, and electrophilic moieties bearing base-susceptible leaving groups include water-soluble primary and secondary polyamines, preferably primary diamines. These include diamines of formula (I) :
  • n is an integer from 2 to 10, preferably 2 to 6. Mention is made of hexamethylenediamine . Also suitable are mixed primary/secondary amines, and mixed primary/secondary/tertiary amines. Mixed primary/secondary amines include those of Formula (II) :
  • Suitable primary/secondary/tertiary amines include compounds like those of formula (II) but modified in that one or more of the hydrogen atoms attached to a non-terminal nitrogen atom of the compound of formula (II) is replaced by a lower aminoalkyl group such as an aminoethyl group.
  • the commercial product of tetraethylenepentamine usually contains some isomers branched at non-terminal nitrogen atoms, so that the molecule contains one or more tertiary a ino groups. All these polyamines are readily soluble in water, which is suitably used as the second continuous phase.
  • Other suitable polyamine reactants include polyvinylamine, polyethyleneimine,
  • Primary and secondary amino groups will react with anhydride moieties.
  • Tertiary amino groups catalyse the reaction of the primary and secondary amino groups.
  • polyetheramines of general formula (III) are also suitable.
  • r is an integer from 1 to 20, preferably 2 to 15, more preferably 2 to 10, and R is hydrogen, methyl or ethyl.
  • R is hydrogen, methyl or ethyl.
  • a reactant is an amine it must contain at least two amino groups capable of reacting with moieties (a) and (b) , i.e., at least two groups that are primary or secondary amino groups.
  • the compound must be, at least, a diamine, but it may contain more than two amino groups; see for example compounds of formula (II) .
  • diamine is used to indicate a compound that has at least two reactive amino groups, but the term does not necessarily exclude reactants that contain more than two amino groups. Similar remarks apply to the term "diol" .
  • Reactants that will react with isocyanates, anhydride moieties, glycidyl moieties, and electrophilic moieties bearing base-susceptible leaving groups also include compounds that contain both amino and hydroxyl groups.
  • monoethanolamine, diethanolamine, triethanolamine, dialkylethanolamines, N-alkyl-diethanolamines and N,N-dimethyl-2-amino (ethoxy) ethanol there are mentioned monoethanolamine, diethanolamine, triethanolamine, dialkylethanolamines, N-alkyl-diethanolamines and N,N-dimethyl-2-amino (ethoxy) ethanol .
  • a material is to be encapsulated in the microcapsules formed, that material is dissolved or dispersed in the solution in the first liquid, together with the reactants comprising the isocyanate and anhydride moieties, glycidyl moieties or electrophilic moieties bearing base- susceptible leaving groups.
  • this material must not be so reactive with the isocyanate or anhydride that it competes significantly with the reaction that creates the membrane. Alcohols can be encapsulated, provided that the isocyanate content of the reactants is low.
  • alcohols will react with anhydride moieties to form acid esters and with isocyanate moieties to form urethanes, these reactions are slow, compared with the reactions between the isocyanate moiety or the anhydride moiety and the amine, so these reactions do not compete significantly with the desired membrane-forming reactions.
  • the rate of the membrane-forming reaction depends on the particular first liquid that is used as the dispersed organic phase.
  • a catalyst can be incorporated with the amine in the aqueous phase to speed the membrane- forming reactions. Suitable catalysts include tertiary amines.
  • the tertiary amine in the amount used, should be freely soluble in the water present in the reaction mixture.
  • the simplest tertiary amine is trimethylamine and this compound, and its C 2 , C 3 and C homologues can be used. It is of course possible to use tertiary amines containing a mixture of alkyl groups, for instance methyldiethylamine .
  • the tertiary amine can contain more than one tertiary amine moiety. It may also contain other functional groups provided that those other functional groups do not interfere with the required reaction, or the functional groups participate beneficially in the required reaction. As an example of a functional group that does not interfere there is mentioned an ether group. As an example of a functional group that does not interfere there is mentioned an ether group. As an example of a functional group that does not interfere there is mentioned an ether group. As an example of a functional group that does not interfere there is mentioned an ether group. As an example of a functional group that does not interfere there is mentioned
  • Suitable tertiary amines include compounds of the following structures :
  • triethylamine TAA
  • TAA triethylamine
  • the amount of the tertiary amine required is not very great. It is conveniently added in the form of a solution containing 0.5g of TEA per lOmL of water. Usually 0.5% by weight of this solution, based on the total weight, suffices, although 0.7% may be required in some cases. The amount used does not usually exceed 1%, although no disadvantage arises if more than 1% is used.
  • Catalysts other than tertiary amines can be used.
  • first liquid can be used. Mention is made of titanium tetraalkoxides available under the trademark Tyzor from DuPont and stannous octanoate, although these should not be used when there is also present in the organic solvent an alcohol to be encapsulated.
  • the ability to encapsulate alcohols is of particular significance.
  • the pheromone of the codling moth is E,E-8,10-C ⁇ 2 alcohol and it has been difficult to encapsulate this pheromone by the previously known technique involving isocyanate.
  • the present invention permits encapsulation of alcoholic compounds, including alcoholic pheromones and should permit encapsulation of codling moth pheromone, provided that the isocyanate content of the reactants is low.
  • Suitable polyols include diols of formula (IV) :
  • n is an integer from 2 to 10 , preferably 2 to 4 , and of formula (V) :
  • m is an integer from 1 to 10 and R is hydrogen or a methyl or ethyl group.
  • R is hydrogen or a methyl or ethyl group.
  • the reactions between molecules (a) and (b) and an alcohol are slower than the reactions between molecules (a) and (b) and an amine.
  • a catalyst can be used and suitable catalysts include the tertiary amines and other catalysts mentioned above. It should be possible to encapsulate an alcohol by means of reactions between isocyanate moieties and anhydride moieties, glycidyl moieties or
  • the first liquid that serves as the dispersed phase, is a liquid in which the first reactant can be dispersed or dissolved and in which any material to be encapsulated can be dispersed or dissolved. It should be immiscible, or at least only partially miscible, with the second liquid. While the limits on what is meant by "partially miscible" are not precise, in general a substance is considered to be water- immiscible if its solubility in water is less than about 0.5% by weight. It is considered to be water-soluble if its solubility is greater than 98%, i.e., if 1 gram of the substance is put in 100 grams of water, 0.98 gram would dissolve.
  • the first liquid is a marginal solvent for the polymer reactant, and has a boiling point in the vicinity of 100°C.
  • the properties of the first liquid which will become encapsulated with the active material that is to be released, will affect the rate of release of that active material. Selection of a first liquid has to be made with these considerations in mind. Suitable candidates for use as the first liquid include alkylbenzenes such as toluene, xylene, ethers such as methyl tert .
  • ketones such as ethylisobutylketone, esters such as ethyl acetate, propyl acetate, halogenated aliphatic hydrocarbons such as dichloromethane, and aliphatic nitriles such as butyronitrile .
  • solvents can be used.
  • co-solvents there are mentioned aliphatic liquids such as kerosene and also cyclic hydrocarbons such as cyclohexane.
  • aliphatic liquids such as kerosene and also cyclic hydrocarbons such as cyclohexane.
  • styrene-maleic anhydride copolymer containing 14% maleic anhydride is soluble in all of these solvents
  • copolymer containing 50% maleic anhydride is soluble only in ethylacetate, dichloromethane and butyronitrile .
  • the second liquid that forms the continuous phase is preferably water or an aqueous solution with water as the major component, or another polar solvent.
  • Surfactants and emulsifiers can be used to assist in dispersion of the first liquid, i.e. the oil phase, in the second liquid.
  • n has an average value from about 9 to about 13.
  • IGEPAL 630 indicating a molecular weight of about 630, is mentioned. IGEPAL 630 is preferred to poly (vinylalcohol) as it results in smaller microcapsules.
  • Other suitable surfactants and emulsifiers include polyethyleneglycol alkyl ethers, for example C ⁇ 8 H 35 (OCH 2 CH 2 ) n OH, where n has an approximate value of about 20, available under the trade-mark BRIJ 98.
  • Ionic surfactants can be used.
  • Sodium dodecyl sulphate (SDS) is mentioned as an example of an anionic surfactant .
  • the first liquid can be dispersed in the second liquid by dropping the first liquid into a stirred bath of the
  • the first liquid then forms droplets throughout the continuous phase of the second liquid.
  • the second reactant may be present in the second liquid before the first liquid is added. In an alternative embodiment, the second reactant is not present in the second liquid when the first liquid has been dispersed, but is added subsequently. In any event, the first and second reactants meet and react at the interface between the continuous and dispersed phases, that is, the surface of the droplets, and react to form the membrane.
  • the membrane-forming reaction can be carried out at a temperature above 0°C, at room temperature or at elevated temperature. If elevated temperature is used, the optimum temperature will depend on the boiling point of each of the solvents that make up the dispersed and continuous phases and that of the material to be encapsulated. No advantage is seen in using a temperature greater than about 70°C.
  • the concentration of each reactant in the liquid will affect the properties of the product. At low concentrations, the formed membranes will be thinner than at higher concentrations. It is preferred that the concentration of the moieties (a) plus (b) is not less than about 2%, and good results have been achieved with concentrations of 5-6%. If the concentration of moieties (a) plus (b) in the first liquid is up to about 10% there will probably be formed discrete microcapsules. At yet higher concentrations, discrete microcapsules are not formed but rather matrix particles in which the first liquid is entrapped. If the concentration is greater than about 15%, there will probably be formed a matrix.
  • hydrophilic and the matrix may be a hydrogel.
  • a copolymer of lower maleic anhydride content say SMA14
  • the membrane formed is amphiphilic rather than hydrophilic.
  • microcapsules When microcapsules are formed from a first liquid having a density less than that of water, they float on top of the liquid present . They can be shipped in this form, or scooped off. When particles of a hydrogel matrix are formed, the liquid can be decanted from the porous solid matrix particles .
  • insect pheromones As examples of materials to be encapsulated, particular mention is made of insect pheromones. In the notation used below to describe the structure of the pheromones, the type (E or Z) and position of the double bond or bonds are given first, the number of carbon atoms in the chain is given next and the nature of the end group is given last. To illustrate, the pheromone Z-10 C19 aldehyde has the structure;
  • Pheromones may in fact be mixtures of compounds with one component of the mixture predominating, or at least being a significant component. Mentioned as examples of significant or predominant components of insect pheromones, with the target species in brackets, are the following: E/Z-ll C14 aldehyde (Eastern Spruce Budworm) , Z-10 C19 aldehyde (Yellow Headed
  • An example of a ketone that is a pheromone is E or Z 7-tetradecen-2-one, which is effective with the oriental beetle.
  • An ether that is not a pheromone but is of value is 4-
  • 17 allylanisole which can be used to render pine trees unattractive to the Southern pine beetle.
  • the product of the microencapsulation process is a plurality of microcapsules having a size in the range of from about 1 to about 5000 ⁇ m, preferably 20 ⁇ m to 2000 ⁇ m. Particularly preferred microcapsules have sizes in the range from about 10 ⁇ m to about 60 ⁇ m, more preferably about 20 to about 30 ⁇ m, and an encapsulated pheromone contained within the membrane.
  • the microcapsules can be used in suspension in water to give a suspension suitable for aerial spraying.
  • the suspension may contain a suspending agent, for instance a gum suspending agent such as guar gum, rhamsan gum or xanthan gum.
  • Suitable light stabilizers include the tertiary phenylene diamine compounds disclosed in Canadian Patent No. 1,179,682, the disclosure of which is incorporated by reference.
  • the light stabilizer can be incorporated by dissolving it, with the pheromone, in the oil phase.
  • Antioxidants and UV absorbers can also be incorporated. Many hindered phenols are known for this purpose. Mention is made of antioxidants available from Ciba-Geigy under the trade-marks Irganox 1010 and 1076. As UV absorbers there are mentioned Tinuvin 292, 400, 123 and 323 available from Ciba-Geigy.
  • a coloured dye or pigment in the microcapsules.
  • the dye should be oil-soluble and can be incorporated, with the pheromone, in the oil phase. It will be used only in a small amount and will not significantly affect the membrane-forming reaction. Alternatively, or additionally, an oil-soluble or oil-
  • dispersible dye can be included in the aqueous suspension of microcapsules, where it is absorbed by the microcapsule shell.
  • Suitable oil-soluble or oil-dispersible dyes can be obtained from DayGlo Color Corporation, Cleveland, Ohio, and include Blaze Orange, Saturn Yellow, Aurora Pink, and the like.
  • Other compounds of interest for encapsulation include mercaptans.
  • Some animals mark territory by means of urine, to discourage other animals from entering that territory. Examples of such animals include preying animals such as wolves, lions, dogs, etc.
  • Ingredients in the urine of such animals include mercaptans.
  • the urine of a wolf includes a mercaptan, and distribution of microcapsules from which this mercaptan is gradually released to define a territory will discourage deer from entering that territory.
  • Other materials that can be encapsulated and used to discourage approach of animals include essences of garlic, putrescent eggs and capsaicin.
  • microcapsules of the invention include perfumes, pharmaceuticals, fragrances, flavouring agents and the like.
  • dodecyl acetate was used as the material to be encapsulated and released.
  • Dodecyl acetate is itself a component of the pheromone of many species, including the pod borer. Its properties also make it valuable as a mimic for other pheromones that contain ester moieties and are free of other active groups such as hydroxyl and aldehyde groups .
  • FIG 1 shows schematically an apparatus used in the examples
  • Figures 2A, 2B, 2C 2D and 2E are optical photomicrographs of capsules produced by Example 1;
  • Figure 3 is an optical photomicrograph of microcapsules produced by Example 2 ;
  • Figure 4 is an optical photomicrograph of microcapsules produced by Example 3 ;
  • Figure 5 is a graphical illustration of release data of microcapsules produced by Examples 1A and 1C.
  • Figure 6 is a graphical illustration of release data of microcapsules produced by Examples 1C and 2.
  • the copolymer was a styrene-maleic anhydride copolymer of 14% maleic anhydride content, molecular weight 224,000, obtained from Aldrich. Distilled water containing 1.3% Igepal 630(30 ml) was stirred for 1-2 minutes and the first liquid, i.e., the oil phase was added. Thereafter, 10 ml of dissolved water in which 2g of TEPA was distilled were added over 2-3 minutes. The procedure was carried out at room temperature.
  • example 1 The procedure of example 1 was repeated with a mixture of lg Mondur MRS and lg SMA14, except that as oil phase there was used 15 ml of an 11:4 mixture of ethyl acetate and dodecyl acetate.
  • the microcapsules formed are shown in Figure 4.
  • release profile is suitable for pheromone-based insect mating control .

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  • Environmental Sciences (AREA)
  • Manufacturing Of Micro-Capsules (AREA)
  • Agricultural Chemicals And Associated Chemicals (AREA)

Abstract

L'invention concerne un procédé relatif à l'élaboration de microcapsules ou de particules d'une matrice, qui consiste à disperser un premier liquide dans un second liquide immiscible ou partiellement miscible, formant ainsi une phase continue. Un liquide comporte différents réactifs qui présentent (a) des fractions isocyanate et (b) des fractions anhydride, glycidyl ou électrophiles à groupes partants, lesquels ont un potentiel réactif vis-à-vis d'une base, et l'autre liquide contient un réactif à groupes réactifs réagissant avec les réactifs du premier liquide, de manière à former une membrane. Les microcapsules ou les particules peuvent encapsuler des matériaux à libération prolongée. L'invention concerne également des microcapsules ou des particules constituées selon le procédé décrit.
PCT/CA2001/000846 2000-06-12 2001-06-11 Procede d'encapsulation reposant sur l'utilisation de fractions isocyanate Ceased WO2001096011A1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AU2001267202A AU2001267202A1 (en) 2000-06-12 2001-06-11 Encapsulation process using isocyanate moieties

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CA2,311,192 2000-06-12
CA 2311192 CA2311192A1 (fr) 2000-06-12 2000-06-12 Methode d'encapsulation a l'aide de reactifs contenant des groupes fonctionnels du type isocyanate

Publications (1)

Publication Number Publication Date
WO2001096011A1 true WO2001096011A1 (fr) 2001-12-20

Family

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Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CA2001/000846 Ceased WO2001096011A1 (fr) 2000-06-12 2001-06-11 Procede d'encapsulation reposant sur l'utilisation de fractions isocyanate

Country Status (3)

Country Link
AU (1) AU2001267202A1 (fr)
CA (1) CA2311192A1 (fr)
WO (1) WO2001096011A1 (fr)

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2003101606A1 (fr) * 2002-05-31 2003-12-11 Mcmaster University Procede pour encapsuler des molecules organiques hydrophobes dans des capsules de polyuree
US8357651B2 (en) 2008-02-11 2013-01-22 Givaudan Sa Aminoplast microcapsules containing fragrance
US20130095158A1 (en) * 2010-06-25 2013-04-18 Cognis Ip Management Gmbh Process For Producing Microcapsules
US8546509B2 (en) 2004-04-08 2013-10-01 Huntsman Textile Effects (Germany) Gmbh Functionalized particles
US8653190B2 (en) 2011-08-08 2014-02-18 3M Innovative Properties Company Curable cyclic anhydride copolymer/silicone composition
FR3001105A1 (fr) * 2013-01-21 2014-07-25 Rotam Agrochem Int Co Ltd Composition agrochimique, sa methode de preparation et son utilisation
CN114515554A (zh) * 2022-01-18 2022-05-20 国家石油天然气管网集团有限公司 一种聚α-烯烃减阻高分子聚合物微胶囊的制备方法

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GB2073697A (en) * 1980-04-10 1981-10-21 Mitsubishi Paper Mills Ltd Process for Producing Microcapsules Having Two-layer Walls
US4487759A (en) * 1980-03-05 1984-12-11 Imperial Chemical Industries Limited Tertiary amine stabilized micro-encapsulated compositions containing behavior modifying compounds
US4876290A (en) * 1987-02-11 1989-10-24 Rhone-Poulenc Chimie Microencapsulation by interfacial polyaddition
EP0551796A2 (fr) * 1992-01-03 1993-07-21 Ciba-Geigy Ag Microcapsules, procédé pour leur préparation et leur application

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US4487759A (en) * 1980-03-05 1984-12-11 Imperial Chemical Industries Limited Tertiary amine stabilized micro-encapsulated compositions containing behavior modifying compounds
GB2073697A (en) * 1980-04-10 1981-10-21 Mitsubishi Paper Mills Ltd Process for Producing Microcapsules Having Two-layer Walls
US4876290A (en) * 1987-02-11 1989-10-24 Rhone-Poulenc Chimie Microencapsulation by interfacial polyaddition
EP0551796A2 (fr) * 1992-01-03 1993-07-21 Ciba-Geigy Ag Microcapsules, procédé pour leur préparation et leur application
US5310721A (en) * 1992-01-03 1994-05-10 Ciba-Geigy Corporation Process for the preparation of microcapsules using a salt of a partial ester of a styrene-maleic anhydride copolymer

Cited By (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2003101606A1 (fr) * 2002-05-31 2003-12-11 Mcmaster University Procede pour encapsuler des molecules organiques hydrophobes dans des capsules de polyuree
JP2005528200A (ja) * 2002-05-31 2005-09-22 マクマスター・ユニバーシテイ ポリウレアカプセル中に疎水性有機分子をカプセル化する方法
AU2003232543B2 (en) * 2002-05-31 2009-01-29 Mcmaster University Method of encapsulating hydrophobic organic molecules in polyurea capsules
US8546509B2 (en) 2004-04-08 2013-10-01 Huntsman Textile Effects (Germany) Gmbh Functionalized particles
US8357651B2 (en) 2008-02-11 2013-01-22 Givaudan Sa Aminoplast microcapsules containing fragrance
US20130095158A1 (en) * 2010-06-25 2013-04-18 Cognis Ip Management Gmbh Process For Producing Microcapsules
US8653190B2 (en) 2011-08-08 2014-02-18 3M Innovative Properties Company Curable cyclic anhydride copolymer/silicone composition
FR3001105A1 (fr) * 2013-01-21 2014-07-25 Rotam Agrochem Int Co Ltd Composition agrochimique, sa methode de preparation et son utilisation
EP2950646A4 (fr) * 2013-01-21 2016-08-17 Rotam Agrochem Int Co Ltd Composition agrochimique, procédé pour sa préparation et utilisation de celle-ci
US10542755B2 (en) 2013-01-21 2020-01-28 Rotam Agrochem International Company Limited Agrochemical composition, method for its preparation and use thereof
CN114515554A (zh) * 2022-01-18 2022-05-20 国家石油天然气管网集团有限公司 一种聚α-烯烃减阻高分子聚合物微胶囊的制备方法

Also Published As

Publication number Publication date
CA2311192A1 (fr) 2001-12-12
AU2001267202A1 (en) 2001-12-24

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